According to a new survey, the resale value of the iPhone 4 in the U.S. has actually grown by more than 10% since April, while the value of Samsung’s smartphone lineup can’t command the same used prices as Apple. Investment firm Piper Jaffray has been monitoring online auctions for popular Apple and Samsung smartphones since mid-march with a value being assigned to the last 50 phones sold. Their data found that Apple’s three year old iPhone 4 gained 10.31% in resale value on eBay, the iPhone 4S dropped by 11.85%, while the iPhone 5 slid just 3.75%. During the same span, eBay prices of Samsung’s Galaxy S III 27.32% while the Galaxy Note II was off 35.54%.

Piper Jaffray’s team also tracks the resale values of smartphones on the bidding site Taobao in China. There, the iPhone 4 also grew in value since April by 1.42% while the iPhone 4 was off 14.32% and the iPhone 5 fell 7.22%. In China, Samsung’s smartphones also failed to hold the same resale value as Apple’s. The Galaxy S III was down 24.17%, the Galaxy Note II fell 23.67% and the company’s latest flagship Galaxy S4 lost 14.39% of its resale value. Munster continued by stating the fact that the iPhone 5 is holding its value better than the Galaxy S4 in China suggests that there is continuing support for Apple’s flagship device. He sees this as important with Apple “maintaining mindshare in the high-end market.”

Munster is also encouraged by the fact that the iPhone 5 isn’t rapidly declining in price, which could signal that customers are either waiting for a new model, or leaning toward Samsung’s Galaxy lineup. The results seem to be consistent with what Piper Jaffray found when it published the results of its first smartphone resale value index back in May. Apple CEO Tim Cook even commented on the strong resale value of iPhones during his company’s most recent quarterly earnings conference call. It’s currently rumored that Apple may join existing cash-paying-trade-in services by taking trade-ins on used iPhones at Apple’s retail stores. Cook said the following regarding the topic:

The residual value of an iPhone stays so high, and there is so much demand for it, and that makes the trade-in programs more lucrative to a win-win from many points of view.